• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.22 no.4
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• pp.87-94
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• 2022

This paper researched a study to find a combination of acquisition scores for 9 dart throws, which is the minimum number of dart tactile throws in 501 point dart games. The maximum score that can be obtained by throwing once in a dart game is 60 points, which can end the perfect dart game with 60 points eight times according to 60×8+21×1=501, and if you earn 21 points once, you can finish the game with 9 throws. This is called 9-dart finish. As such, only 18 and 14 studies on the combination of scores that can obtain 501 points with 9 throws are known, and no studies have been conducted applying the exhaustive search algorithm. This paper proposed a division branch-and-bound algorithm as a method of simplifying the O(2ⁿ) exponential time performance complexity of the typical branch-and-bound method of a exhaustive search method, to polynomial time complexity. The proposed method limited the level to 8, jumped to a quotient level of 501/60, and backtracked to explore only possible score combinations in the previous level. The possible score combinations of the nine perfect games found with the proposed algorithm were 90(101 cases).

• Journal of the Korea Society of Computer and Information
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• v.15 no.8
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• pp.13-21
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• 2010

One of the most distinguished features of the DHP association rules mining algorithm is that it counts the support of hash key combinations composed of k items at phase k-1, and uses the counted support for pruning candidate large itemsets to improve performance. At this time, it is desirable for each hash key combination to have a separate count variable, where it is impossible to allocate the variables owing to memory shortage. So, the algorithm uses a direct hashing mechanism in which several hash key combinations conflict and are counted in a same hash bucket. But the direct hashing mechanism is not efficient because the distribution of hash key combinations is unvalanced by the characteristics sourced from the mining process. This paper proposes a mapped perfect hashing function which maps the region of hash key combinations into a continuous integer space for phase 3 and maximizes the efficiency of direct hashing mechanism. The results of a performance test experimented on 42 test data sets shows that the average performance improvement of the proposed hashing mechanism is 7.3% compared to the existing method, and the highest performance improvement is 16.9%. Also, it shows that the proposed method is more efficient in case the length of transactions or large itemsets are long or the number of total items is large.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.12 no.4
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• pp.93-99
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• 2013

Parts and structures such as piston rod and knuckle joint for the use of hydraulic cylinder are often welded together in some fashion, usually due to cost and process effectiveness. Welding strongly affects the material by the process of heating and subsequent cooling as well as by the fusion process with additional filler material. Furthermore, a weld is usually far from being perfect, containing inclusions, pores, cavities, undercuts etc. As a consequence, fatigue failures appear in welded structures mostly at the welds rather than in the base metal, even if the latter contains notches. For this reason, fatigue analyses are of high practical interest for all welded structures under the action of cyclic loads. This paper describes the influence of welding parameters, material combinations and heat treatment on the fatigue behavior of welded cylinder rod. In addition, statistical characterization of stress-life response in weldment of hydraulic cylinder rod are presented.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2016.05a
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• pp.177-178
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• 2016

The main structure of the building has been used reinforced concrete construction method in Korea. In recent years, it is necessary to demolition of buildings into urban redevelopment. But yet the demolition method is not being developed perfect. It is necessary to develop future deconstruction for safety and environment method. In this study, we surveyed the demolition method has been used in domestic construction. How the combination of these demolition method should be needed. Demolition method combinations were classified as low-rise, high-rise, middle. It suggested method to combine the demolition process of reinforced concrete structure with seven.

• Journal of IKEEE
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• v.23 no.2
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• pp.710-715
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• 2019

We consider parameter estimation in distributed systems in which measurements at local nodes are quantized in a non-regular manner, where multiple codewords are mapped into a single local measurement. For the system with non-regular quantization, to ensure a perfect independent encoding at local nodes, a local measurement can be encoded into a set of a great number of codewords which are transmitted to a fusion node where estimation is conducted with enormous computational cost due to the large cardinality of the sets. In this paper, we propose an efficient estimation technique that can handle the non-regular quantized data by efficiently finding the feasible combination of codewords without searching all of the possible combinations. We conduct experiments to show that the proposed estimation performs well with respect to previous novel techniques with a reasonable complexity.

• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.2
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• pp.351-356
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• 2022

The parity function can be implemented with XOR (exclusive-OR) and XNOR (exclusive NOR) circuit. In this paper we propose a high performance XOR-XNOR circuit. The proposed circuitreduced the internal load capacitance on critical path and implemented with 8 transistors. The circuit produces a perfect output signals for all input combinations. Compared with the previous circuits, the proposed circuit presents the improved characteristics in average propagation delay time, power dissipation, power-delay product (PDP), and energy-delay-product (EDP). The proposed circuits are implemented with standard CMOS 0.18um technology. Computer simulations using SPICE show that the proposed circuit realizes the expected logic functions and achieves a reasonable performance.

• The Korean Journal of Mycology
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• v.26 no.2 s.85
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• pp.287-292
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• 1998

The perfect state of Bipolaris coicis, causing leaf blight of Job's tears, was in duced under in vitro conditions. Eighty nine isolates of the fungus were collected from 17 locations in Korea from 1994 to 1996. They were crossed on Sach's nutrient agar, on which a piece of rice straw was placed, and incubated at $25^{\circ}C$. Pseudothecia were produced only by certain combinations of compatible isolates. Although pseudothecia were usually produced on rice straw two weeks after incubation, asci and ascospores were observed only in a few pseudothecia examined. The pseudothecia were black and globose with protruding ostiolar beaks. The locules were filled with a mass of hyaline and filamentous pseudoparaphyses. Asci were cylindrical to clavate and straight or slightly curved. The ascus wall was bitunicate with short stipes. Ascospores were filiform, hyaline, and arranged parallel to slightly coiled in the asci, measuring $143-166.4{\times}2.6-3.8\;{\mu}m$. Perfect state of the fungus was identified as Cochliobolus nisikadoi (Tsuda, Ueyama & Nishihara Alcorn), based on the morphological characteristics.

• The KIPS Transactions:PartB
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• v.13B no.4 s.107
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• pp.471-478
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• 2006

In this paper, two color contrast evaluation algorithms, W3C and NSSC algorithms are compared and investigated to select proper criteria of the color contrast of text-background color combinations in web documents. The relationship between the color contrast defined by existing formula and the readability rating is not perfect and there is quite a bit of variance, in particular, there is some substantial outlier. I modify the NSSC algorithm to apply all colors and compare the two algorithms to apply same color combinations of web safe colors. A new algorithm considering color temperature feeling as a component of the color contrast is proposed and implemented. As the results of this study, the existing two algorithms are not contradictory to each other, 82% of all color combinations of web safe colors are not proper combinations according to W3C guide which provide severe restriction to select colors in web documents compared to NSSC algorithm. Experimental test shows proposed algorithm is superior to the W3C algorithm with respect to the linearity of relationship between color contrast and readability rating. It means a color temperature feeling is an effective component of a color contrast. But to determine best contribution ratio of the color temperature feeling, further study is required and it is related to Hangul font style and size. The more popular a mobile color display is used, the more important accessibility factor a color contrast will be.

• Journal of Plant Biotechnology
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• v.34 no.3
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• pp.189-195
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• 2007

Helicteres isora is medicinally important plant effective against asthma, diabetes, hypolipidemia, HIV, besides a good source of diosgenin. Seed dormancy and low rate of natural fruit production make this plant a perfect candidate for developing an in vitro method useful for its clonal propagation and further biotechnological developments. This is the first report on in vitro production of this plant. Nodal explants obtained from aseptically germinated seedlings were cultured on MS medium (Murashige and Skoog 1962) fortified with indole-3-acetic acid (IAA) ($0.57-22.83\;{\mu}M$), indole-3-butyric acid (IBA) ($0.41-16.58\;{\mu}M$), 6-benzylaminopurine (BA) ($0.44-17.75\;{\mu}M$) and kinetin (Kin) ($0.46-13.94\;{\mu}M$) either singly or in combinations of IAA + BA, IAA + Kin and BA + Kin. Combinations of cytokinins (BA and Kin) were most suitable for multiple shoot induction and $13.94\;{\mu}M\;Kin\;+\;13.31\;{\mu}M\;BA$ was optimum (79% frequency) associated with high number of microshoots (7.1 shoots per explant) after 20 days of culture. Maximum shoot elongation and proliferation (10 shoots per explant with 4.8 cm average height) was achieved on MS media containing $2.32\;{\mu}M\;Kin\;+\;2.22\;{\mu}M\;BA\;+\;2.85\;{\mu}M\;IAA$. High rooting frequency (70%) was achieved on MS medium (1/2 basal strength) fortified with $4.14\;{\mu}M$ IBA, while activated charcoal showed inhibitory effects on rooting. Hardening was done with 76% survival rate and these plants were growing without any visual defects and morphologically mimicking the naturally growing plants.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.30 no.2 s.245
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• pp.144-152
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• 2006

In order to consider the effect of Karman vortex for mixing, mixing indices are calculated for 4 models of micro channel flows driven from the combinations of a circular cylinder and a oscillating stirrer. And their results are compared to that of a simple straight micro channel flow(model I). The mixing rate is improved 5.5 times by Karman vortex (model II) and 11.0 times by the stirrer(model III) respectively. In case of successive mixing by the cylinder and the stirrer(model IV), $27\%$ of shortening the channel length for the complete mixing as well as 1.37 times improvement of mixing efficiency then model III. And then, variation of mixing indices are much stable comparing with the others. Thus, it is found that the Karman vortex plays a good role as a pre-mixing method. The D2Q9 Lattice Boltzmann methods are used.